Indian government has to reduce fees for some currency exchange platforms for example 18% fee is high for crypto is very high.Paypal fees also very high when compared with other countries. Rules and regulations for trading in Indian stocks are also very tough which ultimately reduce funds inflow.
Government doesn't fix the fees for exchanges, it's done by exchange itself or your talking about capital gains tax? But it's 30% on profits not 18%.
The trading fees for stock is not high like crypto so you might be confusing something here.
India has to reduce the tax rates on crypto, there's no doubt in that and they can actually generate more revenue by decreasing the tax cause it encourages more investors to enter the market as well as to report their tax annually.